Before they became world famous U.S. Olympic athletes, they were just regular kids as revealed in these adorable throwback photos.

U.S. Olympic athletes share adorable throwback photos

Katie Ledecky

She was always smiling in her youth and now as a world-class Olympic swimmer, Katie Ledecky has even more to smile about. The 19-year-old athlete has won four Olympic medals at The Games, including three golds.